P1227: POLATUZUMAB VEDOTIN, RITUXIMAB, AND BENDAMUSTINE COMBINATION IN RELAPSED OR REFRACTORY DIFFUSE LARGE B-CELL LYMPHOMA: A REAL-WORLD DATA FROM TURKEY
Authors: M. S. Dal, B. Uncu Ulu, A. Uzay, O. M. Akay, S. Besisik, M. N. Yenerel, S. Celik, L. Kaynar, O. K. Yucel, B. Deveci, M. Sonmez, O. Mehtap, H. S. Bekoz, C. Sunu, O. Salim, T. Ulas, S. Karti, F. Altuntas, B. Ferhanoglu, T. Firatli Tuglular
Journal: HemaSphere (2022)

Background: Polatuzumab vedotin (Pola) in combination with Bendamustine and Rituximab (BR) is a promising option for patients with relapsed/ refractory (R/R) diffuse large B-cell lymphoma (DLBCL). Aims: Given reduced survival in patients who are unresponsive to subsequent lines of therapy and the toxicity involved, there is an unmet need in the R/R DLBCL setting. We present a retrospective, multicenter, real-world data study consisting of 71 R/R DLBCL patients treated with Pola-BR in the named patient program in Turkey. Methods: We analyzed the data of 71 R/R DLBCL patients who had been treated with Pola-BR through their participation in the named patient program from March 2018 to April 2021 from 32 hematology centers in Turkey. All patients received Polatuzumab vedotin 1.8 mg/kg intravenously (IV) on day 1 of each cycle, Rituximab 375 mg/m2 IV on day 1 of each cycle, and Bendamustine 90 mg/m2 IV on days 1 and 2 of each cycle in any order. Patients were treated for up to six cycles. Each cycle was applied every 21 days. Results: The median age at Pola-BR initiation was 55 (range,19-84). The patients had undergone a median of three lines (range, 2-5 lines) of treatment before Pola-BR treatment (Table 1). The overall response rate was 47.9%, including 32.4% complete response rate when a median of three cycles was applied. With a median follow-up of 5 months, the median OS of our cohort was 5 months. Patients who were chemorefractory to Pola-BR and patients who had ECOG score ≥2 had a worse survival which was almost double in the multivariate analysis (p=0.042 and p=0.029, respectively). The most common adverse events of grades 3-4 were infections and cytopenias. Grade 1-2 anemia, and grade 3-4 neutropenia and thrombocytopenia were the most common hematological toxicities of Pola-BR treatment. Six patients (8.4%) received allogeneic stem cell transplantation after Pola-BR treatment. Summary/Conclusion: The real-world data from our cohort of hard-to-treat and aggressive R/R DLBCL showed the Pola-BR combination is a promising treatment option with a manageable toxicity profile. Table 1. - Patient’s Characteristics Number (%) Age at Pola-BR initiation, years (median) 55 (19-84) Male sex, n (%) 44 (62%) ECOG performance status 0-1, n (%) 45 (63.4%) ≥2, n (%) 26 (36.6%) Histological subtype (Cell of origin) GCB 27 (38%) ABC 23 (32.4%) Unknown 21 (29.6%) Advanced Stage (Stage 3-4) 56 (73%) IPI score 3-5 at diagnosis 42 (61%) Bulky disease (3 7.5 cm), n (%) 23 (32.4%) B symptoms, n (%) 47 (66.2%) Extranodal disease, n (%) 45 (63.4%) Bone marrow involvement, n (%) 18 (25.4%) Abbreviations: Pola-BR: Polatuzumab vedotin, bendamustine and Rituximab; ECOG: Eastern Cooperative Oncology Group; GCB: Germinal center B-cell–like subtype; ABC: Activated B-cell–like subtype; IPI: international prognostic index